Industrial manufacturing processes often include repetitive lifting and transportation of work pieces that are too heavy, too large, too fragile, or must be placed with too high precision to be lifted without mechanical assistance. The lifting and transportation of these work pieces may be accomplished manually or through automated means with material handling devices. Gripping devices allow heavy, large, and complex work pieces to be transported through manufacturing processes with increased reliability and efficiency.
Vacuum-based grippers require backup mechanical clamps capable of maintaining control of the work piece or work pieces in the event of partial or total loss of vacuum pressure. Furthermore, vacuum grippers are capable of generating gripping force in only a single direction (created by air pressure on the opposite side of the vacuum chamber) and may require redundant gripping mechanisms and/or friction to hold the work piece while rotating or moving along more than one axis.
Permanent magnet-based grippers may not require backup mechanical clamps capable of holding the work piece in the event of power loss. However, these grippers often require additional structure to mechanically release the work piece from the gripper and work only on ferrous materials. Additionally, permanent magnet grippers are often incapable of picking up only one work piece from a stack or inventory of work pieces and have difficulty picking up parts of varying shapes.